1. Field of the Invention
The invention is related to providing a seatbelt buckle mounted in a vehicle, and particularly, to providing a multi-purpose buckle sensor assembly including a contact switch and a non-contact switch integrated into one body to detect the locking state and unlocking state of the seatbelt buckle at the same time.
2. Prior Arts
A conventional vehicle buckle is provided with a seatbelt, with which is mounted to a proper place in a vehicle. As being worn by an occupant, the seatbelt passes through and hangs on predetermined positions, for example three points, terminates into the buckle with a tongue connected to its end to be supported. The buckle is known to promote the safety of occupants in an abnormal condition.
The safety seatbelt buckle is supposed to identify on whether a driver and/or an occupant wears the seatbelt. The seatbelt buckle normally includes a mechanical switch such as a micro-switch to be operated with the tongue, together. Therefore, the micro-switch turns on or off in response to the insertion of the tongue thereinto, so that a warning lamp mounted on an instrument panel is lightened or put out to warn the non-wearing of the seatbelt to a driver and/or an occupant.
The safety seatbelt buckle further can include a non-contact switch such as a hall sensor to perform a self-diagnostic function of an electronic control unit such as ECU. Upon the seatbelt non-wearing of the occupant, the non-contact switch detects the abnormal states of the vehicle to force all warning lamps on the instrument panel to be lightened, while it enables the execution of the proper measures related to the traveling of the vehicle such as the limitation of a speed, the ready state for the operation of an airbag, etc. thereby enhancing the efficiency of a vehicle control.
But, the safety seatbelt buckle is configured so that the contact and/or non-contact switches are respectively or together mounted therein to recognize its locking state or non-locking state with being separated from each other. The configuration makes the mutual separated contact and non-contact switches mounted on their proper positions, mainly the bottom surface of a lower case, so the contact and/or non-contact switches are switched in response to the insertion of a tongue into the buckle in a predetermined lapse interval.
For example, a latch, an ejector or a moving member mounted in the buckle to be co-operated with the tongue operates these contact and/or non-contact switches. It means that their mounting place is limited and a separate mounting space is secured. Furthermore, the configuration may cause the malfunction of the switches due to the wrongly insertion of the tongue into the buckle.
In order to resolve these problems, the adoption of a non-contact switch is disclosed in U.S. Pat. No. 5,960,523 (Oct. 5, 1999) which is related to a seat belt buckle sensor. A sensor is used to monitor the presence and position of the tongue either directly or by measuring motion of the latch. For example, the full range of motion of the latch, both in its up and down motion and in its lateral motion in response to the seat belt tension, can be monitored by placing a small magnet on the latch and measuring the magnetic field intensity at a suitable location fixed with respect to the seat belt buckle. The sensor within integrated circuit package is mounted to a fixed portion of a latch follower spring support, which also encloses the guide plate of the latch. Therefore, the magnet is moved along with the latch to be cooperated with the sensor.
Another typical technology is disclosed in U.S. Pat. No. 6,076,239 (Jun. 20, 2000), which is related to a seat belt buckle with slide sensor. The seat belt buckle comprises a belt lock for a safety belt that includes a frame, a latching element for the latching of the belt tongue and a securing element, which secures the latching element in the latched state. A detector device is provided at the belt lock which detects the position of the securing element. The detector device has a hall probe and a magnet secured to the securing element. The hall probe and the magnet only lie close to and opposite one another when the securing element is located in its closed end position. Therefore, the detector device detects the position of the securing element.
But, these seat belt buckles include only one non-contact switch. For it, it has a disadvantage in being not usable for various purposes. Especially, it must sacrifice the feature of quickly warning the non-wearing of a seatbelt to an occupant in using a contact switch or of applying a control signal to an electronic control unit for a self-diagnostic function in using a non-contact switch. Therefore, it is preferable if the advantages of the contact and non-contact switches are used.
In order to use these advantages, to a seatbelt buckle disclosed in European Patent Application EP1088037A2, a locking state detecting apparatus of a vehicle's buckle detected in European Patent Application EP107882A1 can be adapted as follows:
The seatbelt buckle includes a body frame, a release button slidably coupled to the body frame for unlatching a seatbelt tongue from the seatbelt buckle, a locking lever capable of being pivotally rotated about wings by a predetermined angle, a slider for supporting and fixing the locking lever and an ejector for pushing the tongue in a longitudinal direction which is a lengthwise direction of the body frame. The body frame has an arch-shaped supporting beam which is integrally formed with the body frame in a manner such that the supporting beam is elected in a vertical direction. The supporting beam serves to limit movement of the slider and increase structural rigidity of the seatbelt of the seatbelt buckle. The slider has a width, which is greater than that of the body frame, and possesses shock-absorbing means for increasing durability of the seatbelt buckle. The release button has at least two release projections, which are formed with inclined surfaces that are in turn brought into contact with the inclined projections of the sliders.
In the seatbelt buckle, there may be mounted a locking state detecting apparatus of EP107882A1, in which a contact switch and a non-contact switch are mounted on the inner right and left surfaces of the seatbelt buckle, respectively, adjacent to both sides of the body frame.
The seatbelt buckle is positioned in a lower case so that the tongue inserted is not escaped therefrom. For example, as the tongue is pushed into an inserting opening formed in the body frame, an ejector mounted in a slidably opening of a bottom plate is moved rearward. A locking lever, which is positioned on an upper end of the body frame and elastically supported by a spring, is rotated downward about wings to let a latch bar to be locked to the tongue.
At that time, the ejector forces ends projected from its both sides and out of the body frame to operate the contact and non-contact switches at once. The contact switch such as a micro-switch called “mechanical switch” is turned on to interrupt a power source applied to a warning lamp, so it means that the non-wearing of a seat belt is not warned for occupants. The non-contact switch such as a multi-purpose buckle sensor assembly including a hall sensor and a permanent magnet is operated to detect the insertion of the tongue according to the approaching of the permanent close thereto, so that it supplies detecting signals to an electronic control unit (ECU) constituted as part of a vehicle control portion to perform the self-diagnostic function.
Nevertheless, the configuration shows that the contact and non-contact switches are mounted in the lower case to be separated from each other and their corresponding wirings are separated from each other. For it, their mounting is not easy and additional space for their mounting is required. t is difficult to mount the contact and non-contact switches at one place with a good space efficiency and operate them cooperating with the buckle.
Therefore, the configuration causes the contact and non-contact switches to have different operating time points, so it can't make an expression that they are operated with the buckle assembly at the same time. The configuration is not proper for a multi-purpose buckle sensor assembly to which the invention is adapted, which is integrated into one unit. Herein, it is noted that the unified multi-purpose buckle sensor assembly enhances the self-diagnostic function of the electronic control unit in a vehicle.